creating object of another class when initializing an object of a class

Question

Here's what I want to achieve: I'm building a class for controlling step motors. In that class I want to have a method called "init". In that method I'd like to create an object of class Tone, which I'll need to control a motor. BUT I want to have seperate Tone class object for every object of my class that I create. How can I do it?

So, for exmaple, if I have:

myClass newmotor1;
memotor1.init();

After executing these two lines, I'd like to have my object newmotor1 (which I have, because I just created it) AND an object of class Tone, which I'll use.

• Majenko: Why do you want to create it in the init function? Why not just have one in the class already?
• mnj: But I want to have seperate Tone objects for each object of my class
• Majenko: And? What difference does that make?
• mnj: To be honest, I'm not sure what you mean. I'm actually new to classes, objects and all that stuff. Could you explan?
• Majenko: You use a class just like any other variable. Just use it in your class like any other variable.

Answer 1

You don't need to "create" anything. Just have an object in your class:

class Tone {
 public:
 void dosomething() {
 // Whatever is in here
 }
};
class MyMotor {
 public:
 Tone tone;
 void init() {
 // Nothing much else to do in here now.
 }
};

You then:

MyMotor newmotor1;

And you can access:

newmotor1.tone.dosomething();